diff --git a/chart/templates/istio/values.yaml b/chart/templates/istio/values.yaml
index acbeb921e44c397e0f819e913332090a35e00bf4..dca48d62f975a343f901fd27991c05fcdbbcc823 100644
--- a/chart/templates/istio/values.yaml
+++ b/chart/templates/istio/values.yaml
@@ -125,7 +125,7 @@ gateways:
       tls:
         {{- $tlsMode := (dig "tls" "mode" "SIMPLE" $servervalues) }}
         mode: {{ $tlsMode }}
-        {{- if or (eq $tlsMode "SIMPLE") (eq $tlsMode "MUTUAL") }}
+        {{- if or (eq $tlsMode "SIMPLE") (eq $tlsMode "MUTUAL") (eq $tlsMode "OPTIONAL_MUTUAL") }}
         credentialName: {{ $index }}-{{ $name }}-cert
         {{- end }}
         {{- $tlsMinVersion := (dig "tls" "minProtocolVersion" "" $values) }}
@@ -148,7 +148,7 @@ gateways:
       tls:
         {{- $tlsMode := (dig "tls" "mode" "SIMPLE" $values) }}
         mode: {{ $tlsMode }}
-        {{- if or (eq $tlsMode "SIMPLE") (eq $tlsMode "MUTUAL") }}
+        {{- if or (eq $tlsMode "SIMPLE") (eq $tlsMode "MUTUAL") (eq $tlsMode "OPTIONAL_MUTUAL") }}
         credentialName: {{ $name }}-cert
         {{- end }}
         {{- $tlsMinVersion := (dig "tls" "minProtocolVersion" "" $values) }}
@@ -171,7 +171,7 @@ gateways:
       tls:
         {{- $tlsMode := (dig "tls" "mode" "SIMPLE" $values) }}
         mode: {{ $tlsMode }}
-        {{- if or (eq $tlsMode "SIMPLE") (eq $tlsMode "MUTUAL") }}
+        {{- if or (eq $tlsMode "SIMPLE") (eq $tlsMode "MUTUAL") (eq $tlsMode "OPTIONAL_MUTUAL") }}
         credentialName: {{ $name }}-cert
         {{- end }}
         {{- $tlsMinVersion := (dig "tls" "minProtocolVersion" "" $values) }}